any easy way to remove isolator mounting bolts for trolling motor.....thanks

More than likely, you'll need to replace these when you get them out.  I don't think they can be removed without destroying them.  Someone might have a way, but I don't know of one.

If the screw isn't rusted and seized in place and you can remove it leaving just the rubber part,  grab the square top part and pull and stretch it up.  Then take a hacksaw blade and CAREFULLY (don't scratch your boat) and slowly cut the top off.  The remaining part can be pushed thru the boat and pulled out from the inside.

If the screw is rusted in place, the nut will turn on the inside and you'll need to either:

1. Grab it with a set of channel-locks on the inside while turning out the screw on the outside.

or

2.  Cut the top off with a hacksaw and pull the rest thru from the inside. 

You'll want to put some tape on the fiberglass around the bolt so you don't scratch your boat.

I just got some new isolator bolts from Amazon.com.  They seem to have the best prices.